The present invention relates to a development station for use in a low cost copier or printer and, more specifically, to a development station which is disposable when its original supply of toner is exhausted.
It is known to provide, as a unit, a process kit comprising a photosensitive drum, a corona charger, a developing device and a cleaner. The unit is detachably mounted into the main body of an image forming apparatus, such as a copier or printer. One example of such a unit is disclosed in U.S. Pat. No. 4,591,258, which issued on May 27, 1986 in the names of F. Nishino et al and entitled "Safety Means for Process Kit".
Japanese Pat. No. 56/779, published Jan. 9, 1981 in the names of Masaaki Akita et al, relates to a development device having a magnetic roller, an inner wall which surrounds the roller and an outer wall located around and spaced from the inner wall. The walls define a container box that is filled with toner. In order to develop a latent image on a photoconductor advanced past the device, slits are provided in the box on opposite sides of the development roller so that rotation of the roller effects movement of the toner out of one slit, along a development zone adjacent the photoconductor and into the other slit. Toner can be transferred to the latent image as the toner is moved through the development zone. A lid covers the slits and is removed when the development station is to be loaded into a copier or the like. When the supply of toner is exhausted, the development device is removed and a new development device is loaded into the copier.
Both of the devices described above are intended for use with single component developers comprising a toner. No provision is made in either device for handling a two-component developer material comprising carrier particles and toner particles and for replenishment of toner particles into the developer mix as such particles are depleted by development of latent images on the photoconductor. Moreover, the unit as described in the before-mentioned U.S. patent includes a photoconductor and other apparatus which results in the entire unit being relatively expensive to replace. Also, depletion of the toner supply may occur before the photoconductor needs replacement. Thus the customer must pay for a new photoconductor each time the supply of toner in the development station is exhausted, even though the photoconductor does not need replacement. Accordingly, there is a need for a separate development station for two-component developer materials adapted for use in a low cost copier or printer wherein the development station has provision for adding a fresh toner to the developer mix of carrier and toner particles, and wherein the entire development station is so inexpensive that it can be disposed of when the single supply of fresh toner has been exhausted.
Small, light-weight and self-contained development stations may be held in various orientations prior to insertion into the copier or printer. This can leave the toner supply unevenly distributed in a toner supply chamber, and therefor fresh toner may not be uniformly dispensed from the full length of the chamber. Therefore, there is a need to assist feeding of toner particles from a toner supply chamber.
Even when a development station is inexpensive and intended to be disposable after the initial toner supply is exhausted from its sealed chamber, some customers may attempt to reuse the station. For example, a customer might form an opening into the toner supply chamber, pour toner into the chamber and then close the opening. If the new toner supply is not compatible with the carrier particles in the station or with other parts of the copier or printer, it could prevent proper operation or contamination of the station and copier. Accordingly, there is a need for a way to frustrate unwanted replenishment of a toner supply in a disposable development station.